In many industries, including the food, pharmaceutical and electronics industries, it is important to be able to check the microbiological quality of pressurized fluids, whether during transfer of such fluids through lines or whether such fluids are kept in storage tanks.
So far, the standard method used has been to sample, in aseptic conditions, a certain volume of liquid in a receptacle with the aid of a small sample valve and then to test this sample by the usual filtration method or the method described in U.S. Pat. No. 4,777,137 filed on Jan. 15, 1985 and assigned to Millipore Corporation.
It is easy to imagine the risks of "false positives" incurred by these samples and various transfer of samples. Moreover, these different operations waste time and cause delays in receiving the results of the analyses. The invention described below eliminates these risks because the filtration necessary for the analysis, as well as the placing of the filter in contact with the nutrient medium, which is necessary for the development of the microorganisms that are retained on the membrane, can be carried out in the field. Accordingly, this feature simplifies the operations hitherto necessary for the microbiological testing of these liquids.